SUNOCO, INC (R&M)

Incident Narrative

ON 8/31/2010 AT APPROXIMATELY 0130 HOURS, AN OPERATOR WAS IN THE VICINITY OF THE PRESSURE CONTROL VALVE FOR THE 5N INTER-REFINERY PIPELINE (IRPL) SYSTEM. THE VALVE IS PART OF THE PUMP / METER STATION LOCATED INSIDE THE MARCUS HOOK REFINERY. THE OPERATOR NOTICED A STREAM OF LIGHT NAPHTHA, A GASOLINE COMPONENT, COMING OUT OF THE BASE OF THE VALVE AND LANDING IN A HALF DRUM WHICH HAD BEEN LEFT IN PLACE UNDER THE VALVE FROM A PREVIOUS MAINTENANCE JOB. THE OPERATOR NOTIFIED THE CONTROLLER WHO REMOTELY SHUT DOWN AND ISOLATED THE PIPELINE. AN INSTRUMENT TECHNICIAN ASSISTED IN GETTING THE VALVE TO SEAT AND STOP LEAKING. ALL PRODUCT WAS CAPTURED IN A 33 GAL PAN AND THE PAN WAS FILLED. NO PRODUCT REACHED THE GROUND. SINCE THE BI-DIRECTIONAL PIPELINE WAS IN RECEIVING MODE AT THE TIME OF THE LEAK, THE CONTROL VALVE WAS NOT SUBJECT TO PIPELINE PRESSURE. THE MATERIAL WAS RELEASED FROM THE CENTER SHAFT SPRING SEAL AT THE BOTTOM OF THE VALVE WHICH WAS FOUND TO BE CRUSHED. AFTER THE PRESSURE ON THE VALVE WAS REDUCED WHEN THE PIPELINE WAS PLACED INTO RECEIVING MODE FOLLOWING A PREVIOUS SHIPMENT, IT IS BELIEVED THAT THE SEAL RELAXED AND BEGAN TO LEAK. THE VALVE WAS REPAIRED AND RETURNED TO SERVICE. THE CAUSE OF THE DAMAGE TO THE SPRING SEAL IS CURRENTLY UNDER INVESTIGATION.